Experts have suggested several causes for the mutation, including pollution of water sources, the effect of a dwindling population, or radiation changes.

Researchers at the lab said they have observed an increased incidence of deformity, especially among the limbs of salamanders. However, they said in the past two-headed creatures were far more rare.

The Salamander of Israel is an endangered species because of disturbances to its habitat. The soil and water have been polluted, while much of its natural habitat has been destroyed.

Video: Two-headed mutant salamander found in IsraelIBTimes UK

Leon Blaustei, head of the laboratory where the two-headed tadpole was found, has been looking to understand the biological mechanisms of the salamander for many years.

Researchers hope to work with nature and park authorities to maintain and protect existing populations, as well as revive those in danger.

"The lab the salamanders act as a signal for the general health of the environment, because they are so sensitive to pollution and environmental changes and so they are the first to be harmed," researchers said.

This means the two-headed tadpole can help them understand what is going wrong among the wider population.